Reigning champion Jannik Sinner passes Melbourne exam set by Tristan Schoolkate

Jannik Sinner runs for a backhand (Asanka Brendon Ratnayake/AP)

Defending champion Jannik Sinner lost his first set since October but recovered to beat Tristan Schoolkate and reach the third round of the Australian Open.

Sinner has been untouchable in recent months and headed into this contest on a 15-match winning streak in which the only set he had lost was to Argentinian Tomas Martin Etcheverry in the second round of the Shanghai Masters on October 6.